Embodiments of the present invention generally relate to the field of implantable orthopedic medical devices. More particularly, but not exclusively, embodiments of the present invention relate to implants for revision acetabular surgery.
Joints often undergo degenerative changes that necessitate replacing the joint with a prosthetic joint. For example, the hip joint may be replaced with two bearing surfaces between the femoral head and the acetabulum. The first bearing surface is often a prosthesis shell or acetabular cup having a liner that provides an inner bearing surface that receives and cooperates with art artificial femoral head in an articulating relationship to track and accommodate relative movement between the femur and acetabulum.
In at least some instances, a second or subsequent surgery may be performed to replace a prosthetic joint with another replacement prosthetic joint. Such replacement of the original prosthetic joint may be performed for a number of reasons including, for example, the need to remove diseased or degenerated bone. Further, these additional surgeries often require the replacement of the original prostheses with a larger or enhanced prosthetic joint, often referred to as a revision prosthesis. With respect to acetabular revision surgery, an acetabular prosthesis may include additional mounting elements such as, for example, augments that provide additional support and/or stability for the replacement prosthesis. These additional mounting or attachment members are often required due to bone degeneration, bone loss or bone defects in the affected area (i.e., the hip joint). Moreover, such bone deficiencies or defects often present challenges in attaining optimized and structurally sound prosthetic fixation to the host bone. Accordingly, mounting members may be provided in conjunction with a prosthesis system in order to aid the surgeon in achieving optimal fixation of the prosthetic joint, or a component of the prosthetic joint, to a bone of the patient.
Prior attempts to provide such mounting attachments (i.e., augments) with modularity have often fallen short, and instead typically provide a few discrete positions at which the mounting members may be positioned. For example, an ongoing challenge is to align implantable medical devices such as, for example, reconstructive devices, to the natural physiology of a patient. Proper alignment often may at least assist in attaining optimal wear resistance and optimal performance for many devices. Yet, patient anatomical variations present challenges in providing a medical device that may be properly aligned for each patient. For example, contemporary medical devices that address complex revision acetabular surgery may include multiple buttress augment designs that are dedicated for supporting particular sides or areas of the acetabular cup. Yet, the buttress surface of augments is typically shaped or contoured along a fixed angle or angles. Further, such fixed angles often provide an optimal match for the variations for only some patients' anatomies, and may not allow for an optimal match with other patients' anatomies.
Limitations relating to the available angles at which augment devices may be aligned, as well as augment devices having separated hand or orientation designations, among other limitations, often provide obstacles to both the installation and cost of these types of implantable medical devices. For example, medical implants that are provided in multiple directional or hand orientations may add complexity to the surgical procedure. Moreover, the time associated with at least the selection and confirmation that the correct hand side configuration of the medical device has been selected for implantation in a patient may reduce the time available to the surgeon to attain proper alignment and/or positioning of all of components of the medical device during the implantation procedure. Additionally, different hand configurations may increase the costs associated with procuring, storing, and/or otherwise having readily available an appropriate quantity of implantable devices. Moreover, the time and effort during surgery to properly match the fixed angles of buttress surfaces and the acetabular cup with the patient's particular anatomy may adversely impact the time available to the surgeon to address other aspects of the implantation procedure.
Thus, there remains a need for improved orthopedic medical devices for use in revision acetabular surgeries. The present invention addresses this need and provides other benefits and advantages in a novel and non-obvious manner.
One aspect of the present invention relates to a variable angle blade augment that may improve the ability to optimally position for a wide range of patients a buttress augment against a prosthetic acetabular shell on one end and against a host no on the other end. The ease of installation of the variable angle blade augment of the present invention may provide the surgeon with an extended amount of time to optimally position components of an implantable medical device before the construction of the variable angle blade augment is unitized through a mechanical connection, such as, for example, a mechanically tightened ball and socket joint, and/or via use of an adhesive, including, for example, bone cement. Moreover, the present invention provides the ability to optimally position adjacent prosthetic components, as well as the ability to unitize at least some components after stabilizing at least some of the components with bone screws, among other adjustable fixation devices, anchors or components. Such a construction also eliminates the need for left, right and center buttress augment designs. However, in other embodiments, the construction may be configured to facilitate a fit for either left hand or right hand configurations.
Another aspect of the present invention is directed to a variable angle blade augment that includes an augment section and a blade segment. According to some embodiments, the augment section may include a socket wall and an abutment surface. The socket wall may generally define an aperture that is adapted to provide a socket capture mechanism. The abutment surface may be adapted to abut against at least an outer surface of a component of an implantable medical device. Additionally, according to some embodiments, the blade segment may have a body segment and an extension. The body segment may have a first side, a second side, a first end, and a second end. The extension may have a first connector that is adapted for at least pivotally displacement relative to the aperture. Further, the aperture may be adapted to permit linear displacement of the first connector relative to opposing first and second end portions of the aperture.
Another aspect of the present invention is directed to a variable angle blade augment that includes an augment section and a blade portion. The augment section may include a body region that has a front portion, a rear portion, a reservoir, and an aperture. At least a portion of the front portion may be adapted to abut against at least an outer surface of a component of an implantable medical device. Additionally, the reservoir may be in fluid communication with the aperture and adapted to receive the injection of an adhesive that is configured to unitize at least the augment section with the component of the implantable medical device. The blade segment may include a body segment and an extension, with the body segment having a first side, a second side, a first end, and a second end. The extension includes a first connector, at least a portion of which is adapted to be coupled to the augment section by a mechanical connection.
Other aspects of the present invention will become apparent by consideration of the detailed description and the accompanying drawings.
The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, certain embodiments. It should be understood, however, that the present invention is not limited to the arrangements and instrumentalities shown in the attached drawings. Additionally, the description herein makes reference to the accompanying figures wherein like reference numerals refer to like parts throughout the several views.